December 2000 News
Home / Features / Sealed Nut
   Sport Scout Drive Shaft Lip Seal
   By Rick Abbott
In an ongoing effort to eliminate oil leaks from our Indians, I cam up with another step that we are using in machine tools.  On the drive shaft side of the engine there is a mechanical slinger assembly inside the nut that threads the oil back into the engine, or is supposed to when all is new.  

As these nuts get old and things get a little loose, the threaded portion becomes worn.  This allows the oil to pass to the primary where it doesn’t belong.  At original size there should only be about .005” clearance here.  Check yours out; all of mine had .015” to .040”, which will pass considerable oil

For several years we have been eliminating this type of mechanical slinger in machine tools for the very same reason, and with todays lip seals it makes an excellent repair.  All I did was make up a new net assembly bored for a CR lip seal.  The nut is a little thicker overall than the stock one, but so far each SS I have checked had an extra .100” clearance between the sprocket and the nut which worked out just fine.

For those concerned about the seal, the book shows it is good for sustained 8000 rpm use and is oil and gas resistant.  For those running harder with methanol or other fuels, we can go to a different seal material for very little cost.

At present making these things one at a time, they run $ 50.00 including the seal.  If there is enough interest we can make them in the CNC for probably ½ of that.

The material used is Bearcat for extra strength but that might be overkill.  We also surface grind the backside but this might not really be needed either.  Any suggestions just let us know.

Click on pictures for full size

New nut for the drive side main bearing with lip seal.

Seals and nut

Rick can be contacted at:

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